clutch adjusting

I am having a problem with my clutch when I go to start it....I get up to about 8 mph and dump the clutch and it acts like it is slipping slightly or tire wants to slide like it is hanging or something,well anyways when i get down to about 3 to 4mph the engine will start to turn over and fire up,other times the engine will engage at the 10mph or higher when im pedeling....The clutch lever is not hard to pull in and it doesnt slip going down the road....Also I have been having carb problems and It is running rich and I noticed that the exaust smoke was also rolling out the clutch cover on the sprocket side,is this normal?What do I have to do to adjust the clutch?